1. Field of the Invention
The present invention relates to optical tracking and imaging systems and, in particular, to optical tracking and imaging systems for guidance.
2. Description of Related Art
Semi-active laser (SAL) detection or tracking systems are used by the military to support precision laser-guided weapons. With a SAL system, a narrow laser beam of energy is produced and transmitted toward a target. The laser radiation is typically generated and transmitted from a laser target designator (LTD) manned by a forward observer, for example. The forward observer directs the laser radiation to the selected target, thereby designating the target. The SAL seeking system of the laser guided weapon, remotely located from the target and designator, can detect the laser radiation reflected as a pulse signal from the target and assists in guiding the weapon to the target.
Typical SAL systems are designed to scan for the laser pulse at the same frequency as the laser is pulsing. Since the laser pulse operates in an asynchronous mode, it has an unknown time shift. It typically takes time for the SAL system to lock onto the laser pulse and it is possible that the short pulses are not detected by sensors of the seeker, e.g. if only few seconds are available for achieving a lock, a lock may not be achieved.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art systems and methods that allow for improved guidance, such as reduced locking time. The present disclosure provides a solution for these problems.